The
World Health Organization has declared the outbreak of a novel coronavirus (SARS-CoV-2
or 2019-nCoV) as a global pandemic. However, the mechanisms behind the
coronavirus infection are not yet fully understood, nor are there any targeted
treatments or vaccines. In this study, we identified high-binding-affinity aptamers targeting SARS-CoV-2
RBD, using an ACE2 competition-based aptamer selection strategy and a machine
learning screening algorithm. The Kd values of the optimized CoV2-RBD-1C
and CoV2-RBD-4C aptamers against RBD were 5.8 nM and
19.9 nM, respectively. Simulated interaction modeling, along with competitive
with experiments, suggests that two aptamers may have partially identical
binding sites at ACE2 on SARS-CoV-2 RBD. These aptamers present an opportunity
for generating new probes for
recognition of SARS-CoV-2, and could provide assistance in the diagnosis and
treatment of SARS-CoV-2 while providing a new tool for in-depth study of the
mechanisms behind the coronavirus infection.